The present invention relates to a data processing system, and relates in particular to technology for copying data among multiple storage systems belonging to a data processing system.
Technologies for carrying out remote copying in a data processing system that has a host computer and memory systems (e.g. storage systems) including storage areas are known (see JP2004-13367A, for example). Remote copying technology is a technology for copying data stored in a storage area included in one storage system in a data processing system to a storage area included in another storage system. Using remote copying technology, even if a failure should occur in storage system, it is possible for the tasks to be continued in the data processing system by using data stored in another storage system.
When performing remote copying, a copy pair composed of two storage areas included in different storage systems respectively is set. When data is written to one of the storage areas of the copy pair in accordance with a write request from the host computer, a copy of the written data is sent to the storage system having the other storage area and identical data is written to this other storage area as well.
In a data processing system that performs remote copying, there are cases in which one of the storage areas making up a copy pair is changed to another storage area. When changing a storage area making up a copy pair, the pre-change copy pair is deleted, a post-change copy pair is redefined, and initial copying between storage areas making up the post-change copy pair is executed. In the past, access to storage areas in the storage system was suspended by the host computer during the period of the change operation.